1. Field of the invention
The present invention relates generally to the equipment of trunking used to support, house and protect various equipment, for example, and in particular electrical equipment, and to house and to protect cables, conductors and other connections serving such equipment.
In the usual way, in the present context the term xe2x80x9ctrunkingxe2x80x9d refers to a molding comprising a base section, which has an open cross section, and a cover section which is attached to the base station to close it. In practice the cover section is clipped to the base section.
The present invention addresses in particular the situation in which, to attach it to the trunking, equipment is attached to a support which is itself attached to the base section of the trunking.
It is even more particularly directed to the situation in which the support used for this purpose, i.e. to attach equipment to the base section of the trunking, is operative at the outlet of the base section, for example extending between two rims that the trunking has along the free edge of its side flanges.
The present invention relates yet more particularly to the insulating housing which is usually placed around the equipment, at a distance from it, to provide all of the necessary protection against direct access to the active parts of such equipment when the cover section of the trunking is removed, for example if one or more additional cables or conductors have to be installed.
2. Description of the prior art
At present the insulative housing is usually fixed to the back of the base section of the trunking, as is the case with European patent application No. 0 222 116, for example.
However, two problems then arise.
The first is that when the insulative housing extends outward from the back of the base section, the only remaining free space within the base section for the necessary cables or conductors to pass through is reduced to any remaining space laterally of the insulative housing, which can cause difficulties if the insulative housing is relatively wide and/or the trunking is relatively narrow.
The second problem is that the height of the insulative housing must be suited to the height of the trunking.
To this end, European patent application No. 0 222 116 proposes that the insulative housing be made in two parts which are mobile relative to each other in the direction of their height. This makes manufacture singularly more complicated and therefore more costly.
Otherwise, as many insulative housings of different height must be available as there are different heights of trunking to which they are to be fitted.
To overcome at least some of these problems it has been proposed to suspend the insulative housing from the support carrying the equipment concerned, as is the case with international patent application No. 96/11518, for example.
To be more precise, international patent application No. 96/11518 proposes an insulative housing including suspension means enabling it to be attached to an equipment support and a shroud adapted to surround the equipment mounted on the support, at a distance therefrom, the shroud in practice comprising a back and a side wall and therefore being generally cup-shaped.
Unlike an insulative housing fixed to the back of the base section of the trunking, an insulative housing of this kind has the advantage of enabling cables or conductors to pass between it and the back of the base section.
However, the suspension means with which the insulative housing is provided in international patent application No. 96/11518 are reduced to detents which project directly from the side wall of the shroud, at the same level, and cooperate with complementary detents provided for this purpose on the equipment support.
As a result the height at which the insulative housing is suspended in the trunking is fixed, as is the height of the side wall of its shroud.
Thus although an insulative housing of the above kind is suitable for trunking of a given height and/or for a support of a particular kind, it is not necessarily so for trunking of different heights and/or for supports of different kinds.
In particular, for thin trunking, for which a raised support projecting at least partly from the trunking is usually employed, the insulative housing suspended from the support can, as previously, have the very unfavorable effect of reducing the internal volume that remains available for cables or conductors to pass between it and the back of the base section.
A general object of the present invention is to minimize or even eliminate this drawback.
To be more precise, the present invention provides an insulative housing for equipment to be attached to the base section of trunking by means of a support, the housing including suspension means for attaching it to the support and a shroud adapted to surround the equipment attached to the support, at a distance therefrom, the shroud having over at least part of its perimeter a side wall, wherein the suspension means are suspension members which have attachment means at two or more different levels and, over at least a part of its perimeter, at least the top portion of the side wall of its shroud is removable.
The height at which the insulative housing according to the invention is suspended in the trunking can therefore be adjusted optimally according to the height of the trunking and/or the type of support attached to the base section of the trunking.
In other words, the arrangement in accordance with the invention has the advantage that the volume of the insulative housing can be matched optimally to the general configuration of the system to minimize its impact on the usable internal volume of the trunking, leaving in the trunking all the necessary space for the required cables or conductors to pass through.
The features and advantages of the invention will emerge from the following description, which is given by way of example only and with reference to the accompanying diagrammatic drawings.